Force when 2 blocks pushing against each other

A 1000 kg car pushes a 2000 kg truck that has a dead battery. When the driver steps on the accelerator, the drive wheels of the car push against the ground with a force of 4500 N.
What is the magnitude of the force of the car on the truck?
What is the magnitude of the force of the truck on the car?

for the first one
i did 4500/1000 = car's acc = 4.5
4.5 *2000 (trucks mass) = 9000 = wrong